Because it works. Their beliefs can't win in the "marketplace of ideas"--logical analysis and thought always prove conservative ideas to be the best. So the Left brings out their big stick...Hate.
We've been brought up that Hate is a Bad Thing, right? So if they can successfully define somebody as a Hater--racist, homophobic, sexist, whatever--then that person must be a really bad person, and their ideas are automatically discounted. And with liberals controlling the majority of the publicity organs in the country--Hollyweird, the mass media, etc.--and the majority of the colleges, it's very easy for them to define whoever they want as a Hater.
}:-)4
Have you heard some of these kids when they are asked questions?
I'm ready, go ahead and flame me.